The present invention relates to a scroll compressor, and in particular to a scroll compressor with mechanisms for adjusting load and preventing damage due to backflow.
Presently, scroll compressors must rapidly establish a high pressure when starting, have less backflow when stopped, and provide self-adjustment of operating pressure to prevent damage to scrolls, due to exceeded compression ratio.
In U.S. Pat. No. 6,059,549, Tarng, et al. teach a scroll compressor with a sealing arrangement. The scroll compressor comprises a partition dividing the shell thereof into a high-pressure chamber and a low-pressure chamber with a scroll couple therein. A spring and sealing ring are disposed in a hub portion of a fixed scroll, forming a buffer space therebetween. When the scroll compressor starts, the sealing ring is raised by the work flow corresponding to the spring, abutting the bottom surface of a partition. Thus, the sealing ring prevents leakage of the work fluid and achieves required operational pressure rapidly. Due to the additional spring, the sealing ring, however, is forced upwards and unable to descend and release operational pressure in the scroll couple when the compression ratio is exceeded. Therefore, the scroll compressor is unreliable.
In the above arrangement, compressed work fluid poured into the high-pressure chamber immediately reverses into the scroll couple when the scroll compressor stops. This backflow problem generates impact, noise and damage to the end portions of each scroll, thus shortening the life of the scroll compressor.
Furthermore, conventional scroll compressors must keep running when recycling refrigerant. The space between the scroll couple approaches a vacuum, and gas, or gasiform refrigerant, therein is ionized and discharges electricity, damaging the scroll couple.